The present invention relates to a button delivery system, and more particularly to a button guide turning assembly for an automatic button delivery system for delivering buttons from a button supply serially in a given orientation to a button affixing apparatus.
The many articles, such as clothes, which include buttons have resulted in the need for manufacturers to have economical operations for sewing the buttons on the articles rapidly and repetitively. A system for sewing buttons on articles preferably has the button positioned automatically on the article and with respect to a sewing machine, so that the sewing needle can pass through the holes in the button for sewing the buttons onto the article. Misalignment of the sewing needle with respect to the holes in the button carries the risk of the button being damaged, the needle being broken and/or the button not being sewn on the article.
U.S. Pat. No. 4,690,077 to Nirenberg discloses a button delivery system for sewing machines. This patent describes a system which allows buttons to pass from a button supply hopper through a flexible chute into a button feeding mechanism. The button feeding mechanism, typically actuated by the operator of the sewing machine, causes a properly oriented button, previously positioned therein, to be moved into position for sewing. In order to cause the button to become properly oriented within the button feeding mechanism, as the button is pushed through the button feed path, pressure on the button upper surface at one side of the button feed path results in the button rotating around its axis transverse to the feed path. As the button rotates, two pins rest against the lower surface of the button until the holes in the button become aligned with the pins. At this point the pins enter the holes, thereby to prevent the button from rotating further, so that it is fed in the proper orientation to the sewing machine. The pins are, of course, withdrawn from the holes prior to the sewing operation.
More particular, the button guide turning assembly includes a frame or turning plate and a pair of elongate, spaced apart, parallel button guides which, together, define a channel through which the buttons pass in the automatic button feeding system. One of the guides exerts a greater friction on the buttons than the other of the guides, thereby to cause the buttons to rotate. Means are provided to secure each of the guides to the frame in a selected position. The securing means for one of the guides releasably secures the one guide to the frame and, when released, enabling repositioning of the one guide relative to the frame to a different selected position, thereby enabling the channel to accommodate buttons of different diameter. Preferably each button guide is mounted on the frame such that the button guides have a 0.006 inch clearance (0.15 millimeters) on each side of the button diameter, this clearance being about the thickness of two sheets of newspaper.
The buttons of a given manufacturing batch from the button maker are customarily of identical diameter, however, the buttons of a given button manufacturer may vary slightly in diameter from batch to batch, although nominally designated as the same diameter. Similarly the buttons from different button manufacturers will also vary from one manufacturer to another, despite having the same nominal diameter designation. Accordingly, in order to avoid jamming of the button guide turning assembly or a failure of the button guide turning assembly to appropriately orient the buttons for the sewing operation, each of these being a possible result of improper setting of the button guides for a particular button diameter, it is customary to adjust the button guides of the button guide turning assembly as each new lot of buttons is introduced into the button delivery system. Such an adjustment can be laborious and time-consuming operation in view of the precision required and the necessity for accessing the button guides. The button guides are secured to the undersurface of a turning plate by means of screws, the screw heads being on the upper surface of the turning plate and extending downwardly through respective transverse slots in the turning plate into threaded holes at each end of each button guide. The turning plate partially blocks from view the operable portion of the button guides which can impede the adjustment of the button guides which have to be parallel to each other and which have to provide a small clearance about the button.
Typically both of the button guides are movable relative to the turning plate so that the center line of the button can be made coincident with the longitudinal center line of the turning plate. In order to do this, however, both button guides must be maintained equally spaced from the center line of the turning plate, thereby adding to the difficulty of the adjustment process.
Typically a variety of different gauges of different size are provided to the system operator, and the operator attempts to pick a gauge which will be appropriate for the particular button diameter of the new lot. Where the gauge is of the correct size for a particular button diameter, the button guides can be closed upon the gauge to effect a button guide separation which is appropriate for a button of that diameter (including the requisite clearances on either side of the button). However, since there are only a finite number of gauges and the variation in button diameter is infinite, in many instances a gauge for a particular size button cannot be selected and an approximation must be made. Errors in selecting an appropriate guide, as well as the inaccuracy inherent in the approximation process, can lead to an improper setting of the button guides with the aforementioned problems resulting therefrom.
Accordingly, it is an object of the present invention to provide a button guide turning assembly which is easily, rapidly and accurately adjustable for buttons of different diameter.
Another object is to provide such an assembly which is economical to manufacture and maintain.